Couplings are short lengths of pipe used to connect 2 joints of tubing or casing.
They come with painted colour codes on their external surface to indicate their grades.
Couplings are manufactured according to API 5CT and 5B specifications.
API Tubing Coupling:
Specification | ||
Size (Pipe OD) (in) | 1.900, 2-3/8, 2-7/8, 3-1/2, 4, 4-1/2 | |
Upset |
Non Upset External Upset |
|
Grade | J-55, C-75, L-80, N-80, C-95, P-110 | |
Option |
Electro-zinc plated Phosphorised |
API Casing Coupling:
Specification | ||
Size (Pipe OD) (in) | 4-1/2, 5, 5-1/2, 6-5/8, 7, 7-5/8, 8-5/8, 9-5/8, 10-3/4, 11-3/4, 13-3/8, 16, 18-5/8, 20 | |
Threading |
Short Round-Thread Casing (STC) Long Round-Thread Casing (LC) Buttress Thread Casing (BC) |
|
Grade | H-40, J-55, K-55, C-75, L-80, N-80, C-95, AS-95, P-110, L80-13CR |